Summary

The U.S. Endangered Species Act (ESA) has been controversial since it became law nearly 40 years ago. One of its most-debated provisions is citizen involvement in selecting species that become formally protected under the law (“listing”). Citizens can petition the U.S. Fish and Wildlife Service (FWS) to list any unprotected species and can independently use litigation to challenge any FWS listing decision (1, 2). Some contend that these provisions interfere with the ability of FWS to prioritize scarce resources for species that most need protection (e.g., 3, 4).